A pressure sensor having an integrated temperature sensor is proposed in JP-A-2003-75019 and shown in FIG. 4. The pressure sensor 900 is used in a vehicle for measuring pressures in an intake manifold and intake air temperatures. An engine of the vehicle is controlled based on signals indicating the measurements.
A sensor case 910 houses a mold IC 921 including a pressure sensing element 920 that detects pressures. The mold IC 921 is electrically connected to terminals 911 via a lead frame 922. The terminals 911 are provided for outputting pressure signals to an external processing circuit. A port 930 is connected to the case 910 such that a pressure sensing chamber is defined with the case 910 and the port 930. The port 930 has two pressure receiving holes 931 that are formed by dividing the inside of the port 930 with a dividing plate 932.
One of the pressure receiving holes 931 is provided as a medium leading hole 931a through which a pressure transmitting medium is led to the pressure sensing element 920. The other pressure receiving hole 931 is provided as a temperature sensing element housing hole 931b in which a lead wires 924 are arranged. The lead wires 924 are electrically and mechanically connected to the terminals 911 by welding. A temperature sensing element 940 is arranged at about ends of the lead wires 924.
A resin shock absorbing member 925 is arranged in the temperature sensing element housing hole 931b around the lead wires 924 for reducing vibrations of the temperature sensing element 940 and the lead wires 924. If the shock absorbing member 925 is not provided, the temperature sensing element 940 is only supported by the lead wires 924. As a result, the temperature sensing element 940 swings with a connecting point 923 between the lead wires 924 and the terminal 911 as a supporting point when the pressure sensor 900 vibrates.
In such a case, stress is repeatedly applied to the connecting point 923, and the lead wires 924 touch an inner wall of the port 930. As a result, the lead wires 924 are damaged. The lead wires 924 are fixedly supported by the shock absorbing member 925. Thus, the swinging motions of the temperature sensing element 940 and the lead wires 924 are reduced, and their resistance can be improved.
The lead wires 924 are covered with a tube or a coating member for protection from corrosion or grime such that it is not bare in a measurement environment. The connecting point is covered with a potting member 926 for protection. Namely, the pressure sensor 900 requires the tube or the coating member for protecting the lead wires 924, the potting member 926 for protecting the connecting point 923, and the shock absorbing member 925 for supporting the lead wires 924. The lead wires 924 require a complicated configuration for ensuring the vibration resistance of the temperature sensing element 940.